Enhancing Performance and Safety of Medical Implantable Devices with Multiphysics Simulation

The design of an LVAD must take many factors into consideration. The device must be small enough to connect to the heart and be made of compatible materials and geometry that permit the device to reside in the body without being rejected. Fluid dynamics, power supply, and thermal management must also be considered. As multiple interacting physical effects must be accounted for at each area of development, multiphysics simulation is vital to the design process. Freddy Hansen, Sr. R&D Engineer at St. Jude Medical, uses his expertise in physics and mathematical modeling to characterize complex implantable medical devices like LVADs before experimental studies. Hansen has been using COMSOL Multiphysics® software since 2011 and has since created upwards of 230 models that address a wide range of design challenges pertaining to the unique physics of artificial pumping devices. With each generation of LVADs introduced to the market, improvements are made that contribute to enhanced safety and quality of life for the patient. Research and development efforts at St. Jude Medical are centered on improving biocompatibility, hemocompatibility, and immunocompatibility, such that the device does not elicit an adverse immune response, nor interfere with other bodily systems. Geometry and size of the device play an important role in its overall effectiveness. To implant the LVAD, the surgeon connects one end of the LVAD to the left ventricle and the other end to the ascending aorta. If the device is smaller, it is less cumbersome, and less likely to interfere with neighboring organs or tissue. Simulation allows for the evaluation of changes in size or geometry of the LVAD design before implementation of a physical prototype.